The invention is directed to a method of inspecting tires prior to recapping. If an casing which has defects is recapped because the defects were not detected before recapping, various disadvantages occur. Pressurized air in the tire can migrate through the defect, form a pocket between the outer surface of the casing and the new rubber, and at a minimum a bulge is created which produces erratic handling/steering, misalignment problems, vibration, etc. At times the air pressure which builds up between the casing and the new rubber simply blows the old rubber from the casing, and this can be particularly hazardous if it occurs in transit at high speeds. Even if a defect is discovered after a tire has been recapped, this tire cannot be placed on a vehicle because of the danger involved, and obviously the tire must be discarded with the recapper absorbing the cost of labor and materials involved in the recapping operation.
Heretofore defects in tires, such as nail holes and punctures, but including patches and splices, were generally found by either extremely expensive sophisticated detection machinery or laborious manual sight inspection by a person merely shining a light into the interior of a spread tire and looking for defects. The expense of sophisticated high-tech inspection machinery cannot be borne by relatively small retreaders, and obviously manual inspection is time consuming and highly inefficient because it is extremely difficult to visually see defects, particularly small pin holes, punctures, nail holes, etc., when even the brightest of lights is shined against the interior of a dark (black) and generally dirty tire interior.